/*
 *
 *  Copyright 2015-2019 the original author or authors.
 *
 *  Licensed under the Apache License, Version 2.0 (the "License");
 *  you may not use this file except in compliance with the License.
 *  You may obtain a copy of the License at
 *
 *         http://www.apache.org/licenses/LICENSE-2.0
 *
 *  Unless required by applicable law or agreed to in writing, software
 *  distributed under the License is distributed on an "AS IS" BASIS,
 *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 *  See the License for the specific language governing permissions and
 *  limitations under the License.
 *
 *
 */
package springfox.documentation.spring.web.plugins;

import springfox.documentation.spi.service.DocumentationPlugin;

import java.util.LinkedHashMap;
import java.util.List;
import java.util.Map;
import java.util.stream.StreamSupport;

import static java.util.Optional.*;
import static java.util.stream.Collectors.*;

class DuplicateGroupsDetector {
  private DuplicateGroupsDetector() {
    throw new UnsupportedOperationException();
  }

  public static void ensureNoDuplicateGroups(List<DocumentationPlugin> allPlugins) throws IllegalStateException {
    Map<String, List<DocumentationPlugin>> plugins = allPlugins.stream()
        .collect(groupingBy(
            input -> ofNullable(input.getGroupName()).orElse("default"),
            LinkedHashMap::new,
            toList()));


    Iterable<String> duplicateGroups = plugins.entrySet().stream()
        .filter(input -> input.getValue().size() > 1)
        .map(Map.Entry::getKey)
        .collect(toList());
    if (StreamSupport.stream(duplicateGroups.spliterator(), false).count() > 0) {
      throw new IllegalStateException(String.format("Multiple Dockets with the same group name are not supported. "
              + "The following duplicate groups were discovered. %s", String.join(",", duplicateGroups)));
    }
  }


}
